From patchwork Thu May 14 20:37:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kirti Wankhede X-Patchwork-Id: 11549801 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 54847697 for ; Thu, 14 May 2020 21:11:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 32A90206F1 for ; Thu, 14 May 2020 21:11:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="Za9RhaWB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728290AbgENVLL (ORCPT ); Thu, 14 May 2020 17:11:11 -0400 Received: from hqnvemgate25.nvidia.com ([216.228.121.64]:11306 "EHLO hqnvemgate25.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728043AbgENVLL (ORCPT ); Thu, 14 May 2020 17:11:11 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate25.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Thu, 14 May 2020 14:09:53 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Thu, 14 May 2020 14:11:09 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Thu, 14 May 2020 14:11:09 -0700 Received: from HQMAIL105.nvidia.com (172.20.187.12) by HQMAIL109.nvidia.com (172.20.187.15) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 14 May 2020 21:11:08 +0000 Received: from kwankhede-dev.nvidia.com (10.124.1.5) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Thu, 14 May 2020 21:11:02 +0000 From: Kirti Wankhede To: , CC: , , , , , , , , , , , , , , , , , , , , "Kirti Wankhede" Subject: [PATCH Kernel v20 1/8] vfio: UAPI for migration interface for device state Date: Fri, 15 May 2020 02:07:40 +0530 Message-ID: <1589488667-9683-2-git-send-email-kwankhede@nvidia.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1589488667-9683-1-git-send-email-kwankhede@nvidia.com> References: <1589488667-9683-1-git-send-email-kwankhede@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1589490593; bh=s4Iv0GJDj+1bhl4jbE8YcxRvsfl81dyjXBeOzB1RdI0=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:X-NVConfidentiality:MIME-Version: Content-Type; b=Za9RhaWBJIEHPTDn3wz7Zxvugojxj3pLFj1+KscuUb6AvM9P49c6tb+f9c4u1KsM4 vZb5z5IAbsdI4YvvC+YfFUpt+O3GksB3diqS7IS5byw7oRew3dYl7x3gEYNa9yMWZP yEin1+OGaEJJpUnGKFi1tVyW5vMh0PcVQPPYFAL7k8ctqXK+DagiS0PkvN+TLp/YK9 EgealmlljN9tPWR6AbzXLclyuvE2xKXJQGm0t9oTBftMoUvLhur9iIv1FLMFVT6kSk bqcnx55EnM94vcJzEVA5KMwfg9MFAqHNp/O1YEh7YeCu4XpBHXsdUiAsG9VY9q5S/F RdWGRa2fpSUuw== Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org - Defined MIGRATION region type and sub-type. - Defined vfio_device_migration_info structure which will be placed at the 0th offset of migration region to get/set VFIO device related information. Defined members of structure and usage on read/write access. - Defined device states and state transition details. - Defined sequence to be followed while saving and resuming VFIO device. Signed-off-by: Kirti Wankhede Reviewed-by: Neo Jia --- include/uapi/linux/vfio.h | 228 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 228 insertions(+) diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 015516bcfaa3..ad9bb5af3463 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -305,6 +305,7 @@ struct vfio_region_info_cap_type { #define VFIO_REGION_TYPE_PCI_VENDOR_MASK (0xffff) #define VFIO_REGION_TYPE_GFX (1) #define VFIO_REGION_TYPE_CCW (2) +#define VFIO_REGION_TYPE_MIGRATION (3) /* sub-types for VFIO_REGION_TYPE_PCI_* */ @@ -379,6 +380,233 @@ struct vfio_region_gfx_edid { /* sub-types for VFIO_REGION_TYPE_CCW */ #define VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD (1) +/* sub-types for VFIO_REGION_TYPE_MIGRATION */ +#define VFIO_REGION_SUBTYPE_MIGRATION (1) + +/* + * The structure vfio_device_migration_info is placed at the 0th offset of + * the VFIO_REGION_SUBTYPE_MIGRATION region to get and set VFIO device related + * migration information. Field accesses from this structure are only supported + * at their native width and alignment. Otherwise, the result is undefined and + * vendor drivers should return an error. + * + * device_state: (read/write) + * - The user application writes to this field to inform the vendor driver + * about the device state to be transitioned to. + * - The vendor driver should take the necessary actions to change the + * device state. After successful transition to a given state, the + * vendor driver should return success on write(device_state, state) + * system call. If the device state transition fails, the vendor driver + * should return an appropriate -errno for the fault condition. + * - On the user application side, if the device state transition fails, + * that is, if write(device_state, state) returns an error, read + * device_state again to determine the current state of the device from + * the vendor driver. + * - The vendor driver should return previous state of the device unless + * the vendor driver has encountered an internal error, in which case + * the vendor driver may report the device_state VFIO_DEVICE_STATE_ERROR. + * - The user application must use the device reset ioctl to recover the + * device from VFIO_DEVICE_STATE_ERROR state. If the device is + * indicated to be in a valid device state by reading device_state, the + * user application may attempt to transition the device to any valid + * state reachable from the current state or terminate itself. + * + * device_state consists of 3 bits: + * - If bit 0 is set, it indicates the _RUNNING state. If bit 0 is clear, + * it indicates the _STOP state. When the device state is changed to + * _STOP, driver should stop the device before write() returns. + * - If bit 1 is set, it indicates the _SAVING state, which means that the + * driver should start gathering device state information that will be + * provided to the VFIO user application to save the device's state. + * - If bit 2 is set, it indicates the _RESUMING state, which means that + * the driver should prepare to resume the device. Data provided through + * the migration region should be used to resume the device. + * Bits 3 - 31 are reserved for future use. To preserve them, the user + * application should perform a read-modify-write operation on this + * field when modifying the specified bits. + * + * +------- _RESUMING + * |+------ _SAVING + * ||+----- _RUNNING + * ||| + * 000b => Device Stopped, not saving or resuming + * 001b => Device running, which is the default state + * 010b => Stop the device & save the device state, stop-and-copy state + * 011b => Device running and save the device state, pre-copy state + * 100b => Device stopped and the device state is resuming + * 101b => Invalid state + * 110b => Error state + * 111b => Invalid state + * + * State transitions: + * + * _RESUMING _RUNNING Pre-copy Stop-and-copy _STOP + * (100b) (001b) (011b) (010b) (000b) + * 0. Running or default state + * | + * + * 1. Normal Shutdown (optional) + * |------------------------------------->| + * + * 2. Save the state or suspend + * |------------------------->|---------->| + * + * 3. Save the state during live migration + * |----------->|------------>|---------->| + * + * 4. Resuming + * |<---------| + * + * 5. Resumed + * |--------->| + * + * 0. Default state of VFIO device is _RUNNNG when the user application starts. + * 1. During normal shutdown of the user application, the user application may + * optionally change the VFIO device state from _RUNNING to _STOP. This + * transition is optional. The vendor driver must support this transition but + * must not require it. + * 2. When the user application saves state or suspends the application, the + * device state transitions from _RUNNING to stop-and-copy and then to _STOP. + * On state transition from _RUNNING to stop-and-copy, driver must stop the + * device, save the device state and send it to the application through the + * migration region. The sequence to be followed for such transition is given + * below. + * 3. In live migration of user application, the state transitions from _RUNNING + * to pre-copy, to stop-and-copy, and to _STOP. + * On state transition from _RUNNING to pre-copy, the driver should start + * gathering the device state while the application is still running and send + * the device state data to application through the migration region. + * On state transition from pre-copy to stop-and-copy, the driver must stop + * the device, save the device state and send it to the user application + * through the migration region. + * Vendor drivers must support the pre-copy state even for implementations + * where no data is provided to the user before the stop-and-copy state. The + * user must not be required to consume all migration data before the device + * transitions to a new state, including the stop-and-copy state. + * The sequence to be followed for above two transitions is given below. + * 4. To start the resuming phase, the device state should be transitioned from + * the _RUNNING to the _RESUMING state. + * In the _RESUMING state, the driver should use the device state data + * received through the migration region to resume the device. + * 5. After providing saved device data to the driver, the application should + * change the state from _RESUMING to _RUNNING. + * + * reserved: + * Reads on this field return zero and writes are ignored. + * + * pending_bytes: (read only) + * The number of pending bytes still to be migrated from the vendor driver. + * + * data_offset: (read only) + * The user application should read data_offset field from the migration + * region. The user application should read the device data from this + * offset within the migration region during the _SAVING state or write + * the device data during the _RESUMING state. See below for details of + * sequence to be followed. + * + * data_size: (read/write) + * The user application should read data_size to get the size in bytes of + * the data copied in the migration region during the _SAVING state and + * write the size in bytes of the data copied in the migration region + * during the _RESUMING state. + * + * The format of the migration region is as follows: + * ------------------------------------------------------------------ + * |vfio_device_migration_info| data section | + * | | /////////////////////////////// | + * ------------------------------------------------------------------ + * ^ ^ + * offset 0-trapped part data_offset + * + * The structure vfio_device_migration_info is always followed by the data + * section in the region, so data_offset will always be nonzero. The offset + * from where the data is copied is decided by the kernel driver. The data + * section can be trapped, mmapped, or partitioned, depending on how the kernel + * driver defines the data section. The data section partition can be defined + * as mapped by the sparse mmap capability. If mmapped, data_offset must be + * page aligned, whereas initial section which contains the + * vfio_device_migration_info structure, might not end at the offset, which is + * page aligned. The user is not required to access through mmap regardless + * of the capabilities of the region mmap. + * The vendor driver should determine whether and how to partition the data + * section. The vendor driver should return data_offset accordingly. + * + * The sequence to be followed while in pre-copy state and stop-and-copy state + * is as follows: + * a. Read pending_bytes, indicating the start of a new iteration to get device + * data. Repeated read on pending_bytes at this stage should have no side + * effects. + * If pending_bytes == 0, the user application should not iterate to get data + * for that device. + * If pending_bytes > 0, perform the following steps. + * b. Read data_offset, indicating that the vendor driver should make data + * available through the data section. The vendor driver should return this + * read operation only after data is available from (region + data_offset) + * to (region + data_offset + data_size). + * c. Read data_size, which is the amount of data in bytes available through + * the migration region. + * Read on data_offset and data_size should return the offset and size of + * the current buffer if the user application reads data_offset and + * data_size more than once here. + * d. Read data_size bytes of data from (region + data_offset) from the + * migration region. + * e. Process the data. + * f. Read pending_bytes, which indicates that the data from the previous + * iteration has been read. If pending_bytes > 0, go to step b. + * + * The user application can transition from the _SAVING|_RUNNING + * (pre-copy state) to the _SAVING (stop-and-copy) state regardless of the + * number of pending bytes. The user application should iterate in _SAVING + * (stop-and-copy) until pending_bytes is 0. + * + * The sequence to be followed while _RESUMING device state is as follows: + * While data for this device is available, repeat the following steps: + * a. Read data_offset from where the user application should write data. + * b. Write migration data starting at the migration region + data_offset for + * the length determined by data_size from the migration source. + * c. Write data_size, which indicates to the vendor driver that data is + * written in the migration region. Vendor driver must return this write + * operations on consuming data. Vendor driver should apply the + * user-provided migration region data to the device resume state. + * + * If an error occurs during the above sequences, the vendor driver can return + * an error code for next read() or write() operation, which will terminate the + * loop. The user application should then take the next necessary action, for + * example, failing migration or terminating the user application. + * + * For the user application, data is opaque. The user application should write + * data in the same order as the data is received and the data should be of + * same transaction size at the source. + */ + +struct vfio_device_migration_info { + __u32 device_state; /* VFIO device state */ +#define VFIO_DEVICE_STATE_STOP (0) +#define VFIO_DEVICE_STATE_RUNNING (1 << 0) +#define VFIO_DEVICE_STATE_SAVING (1 << 1) +#define VFIO_DEVICE_STATE_RESUMING (1 << 2) +#define VFIO_DEVICE_STATE_MASK (VFIO_DEVICE_STATE_RUNNING | \ + VFIO_DEVICE_STATE_SAVING | \ + VFIO_DEVICE_STATE_RESUMING) + +#define VFIO_DEVICE_STATE_VALID(state) \ + (state & VFIO_DEVICE_STATE_RESUMING ? \ + (state & VFIO_DEVICE_STATE_MASK) == VFIO_DEVICE_STATE_RESUMING : 1) + +#define VFIO_DEVICE_STATE_IS_ERROR(state) \ + ((state & VFIO_DEVICE_STATE_MASK) == (VFIO_DEVICE_STATE_SAVING | \ + VFIO_DEVICE_STATE_RESUMING)) + +#define VFIO_DEVICE_STATE_SET_ERROR(state) \ + ((state & ~VFIO_DEVICE_STATE_MASK) | VFIO_DEVICE_SATE_SAVING | \ + VFIO_DEVICE_STATE_RESUMING) + + __u32 reserved; + __u64 pending_bytes; + __u64 data_offset; + __u64 data_size; +}; + /* * The MSIX mappable capability informs that MSIX data of a BAR can be mmapped * which allows direct access to non-MSIX registers which happened to be within From patchwork Thu May 14 20:37:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kirti Wankhede X-Patchwork-Id: 11549803 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8570F697 for ; Thu, 14 May 2020 21:11:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B1702065F for ; Thu, 14 May 2020 21:11:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="bq6NXs/a" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728311AbgENVLQ (ORCPT ); Thu, 14 May 2020 17:11:16 -0400 Received: from hqnvemgate25.nvidia.com ([216.228.121.64]:11318 "EHLO hqnvemgate25.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728043AbgENVLQ (ORCPT ); Thu, 14 May 2020 17:11:16 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate25.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Thu, 14 May 2020 14:10:00 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Thu, 14 May 2020 14:11:16 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Thu, 14 May 2020 14:11:16 -0700 Received: from HQMAIL105.nvidia.com (172.20.187.12) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 14 May 2020 21:11:15 +0000 Received: from kwankhede-dev.nvidia.com (10.124.1.5) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Thu, 14 May 2020 21:11:09 +0000 From: Kirti Wankhede To: , CC: , , , , , , , , , , , , , , , , , , , , "Kirti Wankhede" Subject: [PATCH Kernel v20 2/8] vfio iommu: Remove atomicity of ref_count of pinned pages Date: Fri, 15 May 2020 02:07:41 +0530 Message-ID: <1589488667-9683-3-git-send-email-kwankhede@nvidia.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1589488667-9683-1-git-send-email-kwankhede@nvidia.com> References: <1589488667-9683-1-git-send-email-kwankhede@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1589490600; bh=uUgKJVCFdD4Zp7du3o0u/sQDLu1K2BjFd3xLP7hSugs=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:X-NVConfidentiality:MIME-Version: Content-Type; b=bq6NXs/abB/KJs/+KBqao9cgajn+SQEpaHKhwfEPJA1BB/F32gDfS7AeDPv0A6aZA DaUWBysBR0ADVX0WFRKFeLmWzp1TlRMF+lfm1YwViYbo5+NjGtC/oweFLlCNNb1BQt +IFAS/01/4djyX5g+5hTL61eqYCFf4FaGE6yQo3gZ7+pif17ZlP73/fDicQZaBVYp9 L88g+ec3cZ4l9kfD8jc1YHtDkNv05LeONRPf+4waDij/CnvxMEJE4AjYgIzz01GN3A OlVA9dFOoMP+FV4XR1VGI2FSPCOU03DhH9Ya8Sh26aeY6zYywkzqXiCMZ39zJfQNKT m6UB0dFmH2mIQ== Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org vfio_pfn.ref_count is always updated while holding iommu->lock, using atomic variable is overkill. Signed-off-by: Kirti Wankhede Reviewed-by: Neo Jia Reviewed-by: Eric Auger Reviewed-by: Cornelia Huck --- drivers/vfio/vfio_iommu_type1.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index a0c60f895b24..fa735047b04d 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -112,7 +112,7 @@ struct vfio_pfn { struct rb_node node; dma_addr_t iova; /* Device address */ unsigned long pfn; /* Host pfn */ - atomic_t ref_count; + unsigned int ref_count; }; struct vfio_regions { @@ -233,7 +233,7 @@ static int vfio_add_to_pfn_list(struct vfio_dma *dma, dma_addr_t iova, vpfn->iova = iova; vpfn->pfn = pfn; - atomic_set(&vpfn->ref_count, 1); + vpfn->ref_count = 1; vfio_link_pfn(dma, vpfn); return 0; } @@ -251,7 +251,7 @@ static struct vfio_pfn *vfio_iova_get_vfio_pfn(struct vfio_dma *dma, struct vfio_pfn *vpfn = vfio_find_vpfn(dma, iova); if (vpfn) - atomic_inc(&vpfn->ref_count); + vpfn->ref_count++; return vpfn; } @@ -259,7 +259,8 @@ static int vfio_iova_put_vfio_pfn(struct vfio_dma *dma, struct vfio_pfn *vpfn) { int ret = 0; - if (atomic_dec_and_test(&vpfn->ref_count)) { + vpfn->ref_count--; + if (!vpfn->ref_count) { ret = put_pfn(vpfn->pfn, dma->prot); vfio_remove_from_pfn_list(dma, vpfn); } From patchwork Thu May 14 20:37:42 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kirti Wankhede X-Patchwork-Id: 11549805 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A9159697 for ; Thu, 14 May 2020 21:11:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8D45E206F1 for ; Thu, 14 May 2020 21:11:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="Iv3Wj2bl" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728318AbgENVLX (ORCPT ); Thu, 14 May 2020 17:11:23 -0400 Received: from hqnvemgate24.nvidia.com ([216.228.121.143]:14325 "EHLO hqnvemgate24.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728294AbgENVLX (ORCPT ); Thu, 14 May 2020 17:11:23 -0400 Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate24.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Thu, 14 May 2020 14:09:05 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Thu, 14 May 2020 14:11:23 -0700 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Thu, 14 May 2020 14:11:23 -0700 Received: from HQMAIL105.nvidia.com (172.20.187.12) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 14 May 2020 21:11:23 +0000 Received: from kwankhede-dev.nvidia.com (10.124.1.5) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Thu, 14 May 2020 21:11:16 +0000 From: Kirti Wankhede To: , CC: , , , , , , , , , , , , , , , , , , , , "Kirti Wankhede" Subject: [PATCH Kernel v20 3/8] vfio iommu: Cache pgsize_bitmap in struct vfio_iommu Date: Fri, 15 May 2020 02:07:42 +0530 Message-ID: <1589488667-9683-4-git-send-email-kwankhede@nvidia.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1589488667-9683-1-git-send-email-kwankhede@nvidia.com> References: <1589488667-9683-1-git-send-email-kwankhede@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1589490545; bh=ZBRmkoeTJZ1FSdM0f83CcxykXlKpxr6CXlXwN8RMx60=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:X-NVConfidentiality:MIME-Version: Content-Type; b=Iv3Wj2blOsVqLChs6/aqnR6VoiHLu+0SnYF7c6Y6gVIyCpd10LojEPUGmCwgWJzds zFTSCy12Jrq1854wtaHuhpI2EtHodBBs+0vknlaFAIgqL8mQb2mPSe9jzOUP5OAB7h QH5aEq2foLEwYVXWcD0YCsCTEzhJWkV5c1QNTBKDr8ytYYWpcSY35Guro4KH/j5qan QrDrVQ3s7tU5ZpZwkCW/2UVFjD3hkxcdMZHDl6PzKvf6ED2lD98DZ/HF5WBSIwTuu/ M2Nv8oAZAQSrN2nIfr+2ZgkNeraWbPFfnzGcgQyTiT/RJBgYizhvtg8+Mq2I/avdS/ t6ezQ9V81ALjw== Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Calculate and cache pgsize_bitmap when iommu->domain_list is updated and iommu->external_domain is set for mdev device. Add iommu->lock protection when cached pgsize_bitmap is accessed. Signed-off-by: Kirti Wankhede Reviewed-by: Neo Jia --- drivers/vfio/vfio_iommu_type1.c | 88 +++++++++++++++++++++++------------------ 1 file changed, 49 insertions(+), 39 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index fa735047b04d..de17787ffece 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -69,6 +69,7 @@ struct vfio_iommu { struct rb_root dma_list; struct blocking_notifier_head notifier; unsigned int dma_avail; + uint64_t pgsize_bitmap; bool v2; bool nesting; }; @@ -805,15 +806,14 @@ static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma) iommu->dma_avail++; } -static unsigned long vfio_pgsize_bitmap(struct vfio_iommu *iommu) +static void vfio_pgsize_bitmap(struct vfio_iommu *iommu) { struct vfio_domain *domain; - unsigned long bitmap = ULONG_MAX; - mutex_lock(&iommu->lock); + iommu->pgsize_bitmap = ULONG_MAX; + list_for_each_entry(domain, &iommu->domain_list, next) - bitmap &= domain->domain->pgsize_bitmap; - mutex_unlock(&iommu->lock); + iommu->pgsize_bitmap &= domain->domain->pgsize_bitmap; /* * In case the IOMMU supports page sizes smaller than PAGE_SIZE @@ -823,12 +823,10 @@ static unsigned long vfio_pgsize_bitmap(struct vfio_iommu *iommu) * granularity while iommu driver can use the sub-PAGE_SIZE size * to map the buffer. */ - if (bitmap & ~PAGE_MASK) { - bitmap &= PAGE_MASK; - bitmap |= PAGE_SIZE; + if (iommu->pgsize_bitmap & ~PAGE_MASK) { + iommu->pgsize_bitmap &= PAGE_MASK; + iommu->pgsize_bitmap |= PAGE_SIZE; } - - return bitmap; } static int vfio_dma_do_unmap(struct vfio_iommu *iommu, @@ -839,19 +837,28 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, size_t unmapped = 0; int ret = 0, retries = 0; - mask = ((uint64_t)1 << __ffs(vfio_pgsize_bitmap(iommu))) - 1; + mutex_lock(&iommu->lock); + + mask = ((uint64_t)1 << __ffs(iommu->pgsize_bitmap)) - 1; + + if (unmap->iova & mask) { + ret = -EINVAL; + goto unlock; + } + + if (!unmap->size || unmap->size & mask) { + ret = -EINVAL; + goto unlock; + } - if (unmap->iova & mask) - return -EINVAL; - if (!unmap->size || unmap->size & mask) - return -EINVAL; if (unmap->iova + unmap->size - 1 < unmap->iova || - unmap->size > SIZE_MAX) - return -EINVAL; + unmap->size > SIZE_MAX) { + ret = -EINVAL; + goto unlock; + } WARN_ON(mask & PAGE_MASK); again: - mutex_lock(&iommu->lock); /* * vfio-iommu-type1 (v1) - User mappings were coalesced together to @@ -930,6 +937,7 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, blocking_notifier_call_chain(&iommu->notifier, VFIO_IOMMU_NOTIFY_DMA_UNMAP, &nb_unmap); + mutex_lock(&iommu->lock); goto again; } unmapped += dma->size; @@ -1045,24 +1053,28 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu, if (map->size != size || map->vaddr != vaddr || map->iova != iova) return -EINVAL; - mask = ((uint64_t)1 << __ffs(vfio_pgsize_bitmap(iommu))) - 1; - - WARN_ON(mask & PAGE_MASK); - /* READ/WRITE from device perspective */ if (map->flags & VFIO_DMA_MAP_FLAG_WRITE) prot |= IOMMU_WRITE; if (map->flags & VFIO_DMA_MAP_FLAG_READ) prot |= IOMMU_READ; - if (!prot || !size || (size | iova | vaddr) & mask) - return -EINVAL; + mutex_lock(&iommu->lock); - /* Don't allow IOVA or virtual address wrap */ - if (iova + size - 1 < iova || vaddr + size - 1 < vaddr) - return -EINVAL; + mask = ((uint64_t)1 << __ffs(iommu->pgsize_bitmap)) - 1; - mutex_lock(&iommu->lock); + WARN_ON(mask & PAGE_MASK); + + if (!prot || !size || (size | iova | vaddr) & mask) { + ret = -EINVAL; + goto out_unlock; + } + + /* Don't allow IOVA or virtual address wrap */ + if (iova + size - 1 < iova || vaddr + size - 1 < vaddr) { + ret = -EINVAL; + goto out_unlock; + } if (vfio_find_dma(iommu, iova, size)) { ret = -EEXIST; @@ -1668,6 +1680,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data, if (!iommu->external_domain) { INIT_LIST_HEAD(&domain->group_list); iommu->external_domain = domain; + vfio_pgsize_bitmap(iommu); } else { kfree(domain); } @@ -1793,6 +1806,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data, } list_add(&domain->next, &iommu->domain_list); + vfio_pgsize_bitmap(iommu); done: /* Delete the old one and insert new iova list */ vfio_iommu_iova_insert_copy(iommu, &iova_copy); @@ -2004,6 +2018,7 @@ static void vfio_iommu_type1_detach_group(void *iommu_data, list_del(&domain->next); kfree(domain); vfio_iommu_aper_expand(iommu, &iova_copy); + vfio_pgsize_bitmap(iommu); } break; } @@ -2136,8 +2151,6 @@ static int vfio_iommu_iova_build_caps(struct vfio_iommu *iommu, size_t size; int iovas = 0, i = 0, ret; - mutex_lock(&iommu->lock); - list_for_each_entry(iova, &iommu->iova_list, list) iovas++; @@ -2146,17 +2159,14 @@ static int vfio_iommu_iova_build_caps(struct vfio_iommu *iommu, * Return 0 as a container with a single mdev device * will have an empty list */ - ret = 0; - goto out_unlock; + return 0; } size = sizeof(*cap_iovas) + (iovas * sizeof(*cap_iovas->iova_ranges)); cap_iovas = kzalloc(size, GFP_KERNEL); - if (!cap_iovas) { - ret = -ENOMEM; - goto out_unlock; - } + if (!cap_iovas) + return -ENOMEM; cap_iovas->nr_iovas = iovas; @@ -2169,8 +2179,6 @@ static int vfio_iommu_iova_build_caps(struct vfio_iommu *iommu, ret = vfio_iommu_iova_add_cap(caps, cap_iovas, size); kfree(cap_iovas); -out_unlock: - mutex_unlock(&iommu->lock); return ret; } @@ -2215,11 +2223,13 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, info.cap_offset = 0; /* output, no-recopy necessary */ } + mutex_lock(&iommu->lock); info.flags = VFIO_IOMMU_INFO_PGSIZES; - info.iova_pgsizes = vfio_pgsize_bitmap(iommu); + info.iova_pgsizes = iommu->pgsize_bitmap; ret = vfio_iommu_iova_build_caps(iommu, &caps); + mutex_unlock(&iommu->lock); if (ret) return ret; From patchwork Thu May 14 20:37:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kirti Wankhede X-Patchwork-Id: 11549807 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 58142697 for ; Thu, 14 May 2020 21:11:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3EE9C2065F for ; Thu, 14 May 2020 21:11:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="SmXz/4m0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728332AbgENVLa (ORCPT ); Thu, 14 May 2020 17:11:30 -0400 Received: from hqnvemgate24.nvidia.com ([216.228.121.143]:14349 "EHLO hqnvemgate24.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728319AbgENVLa (ORCPT ); Thu, 14 May 2020 17:11:30 -0400 Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate24.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Thu, 14 May 2020 14:09:12 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Thu, 14 May 2020 14:11:29 -0700 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Thu, 14 May 2020 14:11:29 -0700 Received: from HQMAIL105.nvidia.com (172.20.187.12) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 14 May 2020 21:11:29 +0000 Received: from kwankhede-dev.nvidia.com (10.124.1.5) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Thu, 14 May 2020 21:11:23 +0000 From: Kirti Wankhede To: , CC: , , , , , , , , , , , , , , , , , , , , "Kirti Wankhede" Subject: [PATCH Kernel v20 4/8] vfio iommu: Add ioctl definition for dirty pages tracking Date: Fri, 15 May 2020 02:07:43 +0530 Message-ID: <1589488667-9683-5-git-send-email-kwankhede@nvidia.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1589488667-9683-1-git-send-email-kwankhede@nvidia.com> References: <1589488667-9683-1-git-send-email-kwankhede@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1589490552; bh=7skbcRjTpE5J4BrETbG3/j023kmrIrZpwcbOzE+xq2I=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:X-NVConfidentiality:MIME-Version: Content-Type; b=SmXz/4m0VvL+i3KPiHksW9rlBVCN2lk7fQT5iSDCwgN9NJraxMVo9AmMoKDLXBhah 11T9dBBrl1dq1MbSRond4KtIswaAnKQDXWkvNCRXOro3AgGXb1ScLdUm2+id3BGV9+ FYzxuTch6KlNnsb2k0sGxu3m5gqnNwmrCT5alBzrWkXVWtkopGsSzvt5Dbj87nOy4m qCqNcLWa3eJDn1aPpID1+jFtW3CuxtzS8AjNQ8Gpl06iqK5D/dv/NxyQDKpHoXi9Bj oNqTyH+zT1pZVt2rVSj1ksntwhjHo5AXW+UPfn60onwxXTRxb7u/0NHnExHmJm9Mug XtKk7R1PpZCFg== Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org IOMMU container maintains a list of all pages pinned by vfio_pin_pages API. All pages pinned by vendor driver through this API should be considered as dirty during migration. When container consists of IOMMU capable device and all pages are pinned and mapped, then all pages are marked dirty. Added support to start/stop dirtied pages tracking and to get bitmap of all dirtied pages for requested IO virtual address range. Signed-off-by: Kirti Wankhede Reviewed-by: Neo Jia --- include/uapi/linux/vfio.h | 55 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index ad9bb5af3463..123de3bc2dce 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -1033,6 +1033,12 @@ struct vfio_iommu_type1_dma_map { #define VFIO_IOMMU_MAP_DMA _IO(VFIO_TYPE, VFIO_BASE + 13) +struct vfio_bitmap { + __u64 pgsize; /* page size for bitmap in bytes */ + __u64 size; /* in bytes */ + __u64 __user *data; /* one bit per page */ +}; + /** * VFIO_IOMMU_UNMAP_DMA - _IOWR(VFIO_TYPE, VFIO_BASE + 14, * struct vfio_dma_unmap) @@ -1059,6 +1065,55 @@ struct vfio_iommu_type1_dma_unmap { #define VFIO_IOMMU_ENABLE _IO(VFIO_TYPE, VFIO_BASE + 15) #define VFIO_IOMMU_DISABLE _IO(VFIO_TYPE, VFIO_BASE + 16) +/** + * VFIO_IOMMU_DIRTY_PAGES - _IOWR(VFIO_TYPE, VFIO_BASE + 17, + * struct vfio_iommu_type1_dirty_bitmap) + * IOCTL is used for dirty pages tracking. + * Caller should set flag depending on which operation to perform, details as + * below: + * + * When IOCTL is called with VFIO_IOMMU_DIRTY_PAGES_FLAG_START set, indicates + * migration is active and IOMMU module should track pages which are dirtied or + * potentially dirtied by device. + * Dirty pages are tracked until tracking is stopped by user application by + * setting VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP flag. + * + * When IOCTL is called with VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP set, indicates + * IOMMU should stop tracking dirtied pages. + * + * When IOCTL is called with VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP flag set, + * IOCTL returns dirty pages bitmap for IOMMU container during migration for + * given IOVA range. User must provide data[] as the structure + * vfio_iommu_type1_dirty_bitmap_get through which user provides IOVA range and + * pgsize. This interface supports to get bitmap of smallest supported pgsize + * only and can be modified in future to get bitmap of specified pgsize. + * User must allocate memory for bitmap, zero the bitmap memory and set size + * of allocated memory in bitmap.size field. One bit is used to represent one + * page consecutively starting from iova offset. User should provide page size + * in bitmap.pgsize field. Bit set in bitmap indicates page at that offset from + * iova is dirty. Caller must set argsz including size of structure + * vfio_iommu_type1_dirty_bitmap_get. + * + * Only one of the flags _START, STOP and _GET may be specified at a time. + * + */ +struct vfio_iommu_type1_dirty_bitmap { + __u32 argsz; + __u32 flags; +#define VFIO_IOMMU_DIRTY_PAGES_FLAG_START (1 << 0) +#define VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP (1 << 1) +#define VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP (1 << 2) + __u8 data[]; +}; + +struct vfio_iommu_type1_dirty_bitmap_get { + __u64 iova; /* IO virtual address */ + __u64 size; /* Size of iova range */ + struct vfio_bitmap bitmap; +}; + +#define VFIO_IOMMU_DIRTY_PAGES _IO(VFIO_TYPE, VFIO_BASE + 17) + /* -------- Additional API for SPAPR TCE (Server POWERPC) IOMMU -------- */ /* From patchwork Thu May 14 20:37:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kirti Wankhede X-Patchwork-Id: 11549809 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1750E697 for ; Thu, 14 May 2020 21:11:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ECFF12065F for ; Thu, 14 May 2020 21:11:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="kQaaEri2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728333AbgENVLi (ORCPT ); Thu, 14 May 2020 17:11:38 -0400 Received: from hqnvemgate25.nvidia.com ([216.228.121.64]:11342 "EHLO hqnvemgate25.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728240AbgENVLh (ORCPT ); Thu, 14 May 2020 17:11:37 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate25.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Thu, 14 May 2020 14:10:21 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Thu, 14 May 2020 14:11:37 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Thu, 14 May 2020 14:11:37 -0700 Received: from HQMAIL105.nvidia.com (172.20.187.12) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 14 May 2020 21:11:37 +0000 Received: from kwankhede-dev.nvidia.com (10.124.1.5) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Thu, 14 May 2020 21:11:29 +0000 From: Kirti Wankhede To: , CC: , , , , , , , , , , , , , , , , , , , , "Kirti Wankhede" Subject: [PATCH Kernel v20 5/8] vfio iommu: Implementation of ioctl for dirty pages tracking Date: Fri, 15 May 2020 02:07:44 +0530 Message-ID: <1589488667-9683-6-git-send-email-kwankhede@nvidia.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1589488667-9683-1-git-send-email-kwankhede@nvidia.com> References: <1589488667-9683-1-git-send-email-kwankhede@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1589490621; bh=3aqFaBUbTlM9CiZVt7kcqBx7tcqeAQ44vTGKcNuMv14=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:X-NVConfidentiality:MIME-Version: Content-Type; b=kQaaEri2a3RHO+WNYF4uGnAf0xt16zj/1s8aWnn3JTEjW/JVBqcLdajuvj+Pz1geT HGAH2A0MHQXIcLUnssBbhuEyvwhypQqQJZP73Rx8Fa/JHDBMNYaoeeC2eCnIdj/Dbs 9JrL4UrzO2xyWyqf9gOe1Eodujk6DOPozQ+l4vcppjYy79HFuXP/a/yANgHnOOwMlY mxbyOqDC+KLoiJESp/VDAkBeIJYRZBQPUvHkuT49e4igpyxFRwQZgoeR4XPtNTMRUk BZ1H2/kFwG/6ExKZZSZS7+uKoCbx9Ho5eahM0ypxF2v6bVCFmKahHW8zQvo2O+tS2R jKbf55tfrH1xA== Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org VFIO_IOMMU_DIRTY_PAGES ioctl performs three operations: - Start dirty pages tracking while migration is active - Stop dirty pages tracking. - Get dirty pages bitmap. Its user space application's responsibility to copy content of dirty pages from source to destination during migration. To prevent DoS attack, memory for bitmap is allocated per vfio_dma structure. Bitmap size is calculated considering smallest supported page size. Bitmap is allocated for all vfio_dmas when dirty logging is enabled Bitmap is populated for already pinned pages when bitmap is allocated for a vfio_dma with the smallest supported page size. Update bitmap from pinning functions when tracking is enabled. When user application queries bitmap, check if requested page size is same as page size used to populated bitmap. If it is equal, copy bitmap, but if not equal, return error. Signed-off-by: Kirti Wankhede Reviewed-by: Neo Jia Fixed error reported by build bot by changing pgsize type from uint64_t to size_t. Reported-by: kbuild test robot --- drivers/vfio/vfio_iommu_type1.c | 294 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 288 insertions(+), 6 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index de17787ffece..b76d3b14abfd 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -72,6 +72,7 @@ struct vfio_iommu { uint64_t pgsize_bitmap; bool v2; bool nesting; + bool dirty_page_tracking; }; struct vfio_domain { @@ -92,6 +93,7 @@ struct vfio_dma { bool lock_cap; /* capable(CAP_IPC_LOCK) */ struct task_struct *task; struct rb_root pfn_list; /* Ex-user pinned pfn list */ + unsigned long *bitmap; }; struct vfio_group { @@ -126,6 +128,19 @@ struct vfio_regions { #define IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu) \ (!list_empty(&iommu->domain_list)) +#define DIRTY_BITMAP_BYTES(n) (ALIGN(n, BITS_PER_TYPE(u64)) / BITS_PER_BYTE) + +/* + * Input argument of number of bits to bitmap_set() is unsigned integer, which + * further casts to signed integer for unaligned multi-bit operation, + * __bitmap_set(). + * Then maximum bitmap size supported is 2^31 bits divided by 2^3 bits/byte, + * that is 2^28 (256 MB) which maps to 2^31 * 2^12 = 2^43 (8TB) on 4K page + * system. + */ +#define DIRTY_BITMAP_PAGES_MAX ((u64)INT_MAX) +#define DIRTY_BITMAP_SIZE_MAX DIRTY_BITMAP_BYTES(DIRTY_BITMAP_PAGES_MAX) + static int put_pfn(unsigned long pfn, int prot); /* @@ -176,6 +191,74 @@ static void vfio_unlink_dma(struct vfio_iommu *iommu, struct vfio_dma *old) rb_erase(&old->node, &iommu->dma_list); } + +static int vfio_dma_bitmap_alloc(struct vfio_dma *dma, size_t pgsize) +{ + uint64_t npages = dma->size / pgsize; + + if (npages > DIRTY_BITMAP_PAGES_MAX) + return -EINVAL; + + dma->bitmap = kvzalloc(DIRTY_BITMAP_BYTES(npages), GFP_KERNEL); + if (!dma->bitmap) + return -ENOMEM; + + return 0; +} + +static void vfio_dma_bitmap_free(struct vfio_dma *dma) +{ + kfree(dma->bitmap); + dma->bitmap = NULL; +} + +static void vfio_dma_populate_bitmap(struct vfio_dma *dma, size_t pgsize) +{ + struct rb_node *p; + + for (p = rb_first(&dma->pfn_list); p; p = rb_next(p)) { + struct vfio_pfn *vpfn = rb_entry(p, struct vfio_pfn, node); + + bitmap_set(dma->bitmap, (vpfn->iova - dma->iova) / pgsize, 1); + } +} + +static int vfio_dma_bitmap_alloc_all(struct vfio_iommu *iommu, size_t pgsize) +{ + struct rb_node *n = rb_first(&iommu->dma_list); + + for (; n; n = rb_next(n)) { + struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node); + int ret; + + ret = vfio_dma_bitmap_alloc(dma, pgsize); + if (ret) { + struct rb_node *p = rb_prev(n); + + for (; p; p = rb_prev(p)) { + struct vfio_dma *dma = rb_entry(n, + struct vfio_dma, node); + + vfio_dma_bitmap_free(dma); + } + return ret; + } + vfio_dma_populate_bitmap(dma, pgsize); + } + return 0; +} + +static void vfio_dma_bitmap_free_all(struct vfio_iommu *iommu) +{ + struct rb_node *n = rb_first(&iommu->dma_list); + + for (; n; n = rb_next(n)) { + struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node); + + vfio_dma_bitmap_free(dma); + } +} + /* * Helper Functions for host iova-pfn list */ @@ -568,6 +651,17 @@ static int vfio_iommu_type1_pin_pages(void *iommu_data, vfio_unpin_page_external(dma, iova, do_accounting); goto pin_unwind; } + + if (iommu->dirty_page_tracking) { + unsigned long pgshift = __ffs(iommu->pgsize_bitmap); + + /* + * Bitmap populated with the smallest supported page + * size + */ + bitmap_set(dma->bitmap, + (vpfn->iova - dma->iova) >> pgshift, 1); + } } ret = i; @@ -802,6 +896,7 @@ static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma) vfio_unmap_unpin(iommu, dma, true); vfio_unlink_dma(iommu, dma); put_task_struct(dma->task); + vfio_dma_bitmap_free(dma); kfree(dma); iommu->dma_avail++; } @@ -829,6 +924,80 @@ static void vfio_pgsize_bitmap(struct vfio_iommu *iommu) } } +static int update_user_bitmap(u64 __user *bitmap, struct vfio_dma *dma, + dma_addr_t base_iova, size_t pgsize) +{ + unsigned long pgshift = __ffs(pgsize); + unsigned long nbits = dma->size >> pgshift; + unsigned long bit_offset = (dma->iova - base_iova) >> pgshift; + unsigned long copy_offset = bit_offset / BITS_PER_LONG; + unsigned long shift = bit_offset % BITS_PER_LONG; + unsigned long leftover; + + if (shift) { + bitmap_shift_left(dma->bitmap, dma->bitmap, shift, + nbits + shift); + + if (copy_from_user(&leftover, (u64 *)bitmap + copy_offset, + sizeof(leftover))) + return -EFAULT; + + bitmap_or(dma->bitmap, dma->bitmap, &leftover, shift); + } + + if (copy_to_user((u64 *)bitmap + copy_offset, dma->bitmap, + DIRTY_BITMAP_BYTES(nbits + shift))) + return -EFAULT; + + return 0; +} + +static int vfio_iova_dirty_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu, + dma_addr_t iova, size_t size, size_t pgsize) +{ + struct vfio_dma *dma; + dma_addr_t i = iova, limit = iova + size; + unsigned long pgshift = __ffs(pgsize); + size_t sz = size; + int ret; + + while ((dma = vfio_find_dma(iommu, i, sz))) { + + /* mark all pages dirty if all pages are pinned and mapped. */ + if (dma->iommu_mapped) + bitmap_set(dma->bitmap, 0, dma->size >> pgshift); + + ret = update_user_bitmap(bitmap, dma, iova, pgsize); + if (ret) + return ret; + + /* + * Re-populate bitmap to include all pinned pages which are + * considered as dirty but exclude pages which are unpinned and + * pages which are marked dirty by vfio_dma_rw() + */ + bitmap_clear(dma->bitmap, 0, dma->size >> pgshift); + vfio_dma_populate_bitmap(dma, pgsize); + + i = dma->iova + dma->size; + if (i >= limit) + break; + + sz = limit - i; + } + + return 0; +} + +static int verify_bitmap_size(uint64_t npages, uint64_t bitmap_size) +{ + if (!npages || !bitmap_size || (bitmap_size > DIRTY_BITMAP_SIZE_MAX) || + (bitmap_size < DIRTY_BITMAP_BYTES(npages))) + return -EINVAL; + + return 0; +} + static int vfio_dma_do_unmap(struct vfio_iommu *iommu, struct vfio_iommu_type1_dma_unmap *unmap) { @@ -1046,7 +1215,7 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu, unsigned long vaddr = map->vaddr; size_t size = map->size; int ret = 0, prot = 0; - uint64_t mask; + size_t pgsize; struct vfio_dma *dma; /* Verify that none of our __u64 fields overflow */ @@ -1061,11 +1230,11 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu, mutex_lock(&iommu->lock); - mask = ((uint64_t)1 << __ffs(iommu->pgsize_bitmap)) - 1; + pgsize = (size_t)1 << __ffs(iommu->pgsize_bitmap); - WARN_ON(mask & PAGE_MASK); + WARN_ON((pgsize - 1) & PAGE_MASK); - if (!prot || !size || (size | iova | vaddr) & mask) { + if (!prot || !size || (size | iova | vaddr) & (pgsize - 1)) { ret = -EINVAL; goto out_unlock; } @@ -1142,6 +1311,12 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu, else ret = vfio_pin_map_dma(iommu, dma, size); + if (!ret && iommu->dirty_page_tracking) { + ret = vfio_dma_bitmap_alloc(dma, pgsize); + if (ret) + vfio_remove_dma(iommu, dma); + } + out_unlock: mutex_unlock(&iommu->lock); return ret; @@ -2288,6 +2463,104 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, return copy_to_user((void __user *)arg, &unmap, minsz) ? -EFAULT : 0; + } else if (cmd == VFIO_IOMMU_DIRTY_PAGES) { + struct vfio_iommu_type1_dirty_bitmap dirty; + uint32_t mask = VFIO_IOMMU_DIRTY_PAGES_FLAG_START | + VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP | + VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP; + int ret = 0; + + if (!iommu->v2) + return -EACCES; + + minsz = offsetofend(struct vfio_iommu_type1_dirty_bitmap, + flags); + + if (copy_from_user(&dirty, (void __user *)arg, minsz)) + return -EFAULT; + + if (dirty.argsz < minsz || dirty.flags & ~mask) + return -EINVAL; + + /* only one flag should be set at a time */ + if (__ffs(dirty.flags) != __fls(dirty.flags)) + return -EINVAL; + + if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_START) { + size_t pgsize; + + mutex_lock(&iommu->lock); + pgsize = 1 << __ffs(iommu->pgsize_bitmap); + if (!iommu->dirty_page_tracking) { + ret = vfio_dma_bitmap_alloc_all(iommu, pgsize); + if (!ret) + iommu->dirty_page_tracking = true; + } + mutex_unlock(&iommu->lock); + return ret; + } else if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP) { + mutex_lock(&iommu->lock); + if (iommu->dirty_page_tracking) { + iommu->dirty_page_tracking = false; + vfio_dma_bitmap_free_all(iommu); + } + mutex_unlock(&iommu->lock); + return 0; + } else if (dirty.flags & + VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP) { + struct vfio_iommu_type1_dirty_bitmap_get range; + unsigned long pgshift; + size_t data_size = dirty.argsz - minsz; + size_t iommu_pgsize; + + if (!data_size || data_size < sizeof(range)) + return -EINVAL; + + if (copy_from_user(&range, (void __user *)(arg + minsz), + sizeof(range))) + return -EFAULT; + + if (range.iova + range.size < range.iova) + return -EINVAL; + if (!access_ok((void __user *)range.bitmap.data, + range.bitmap.size)) + return -EINVAL; + + pgshift = __ffs(range.bitmap.pgsize); + ret = verify_bitmap_size(range.size >> pgshift, + range.bitmap.size); + if (ret) + return ret; + + mutex_lock(&iommu->lock); + + iommu_pgsize = (size_t)1 << __ffs(iommu->pgsize_bitmap); + + /* allow only smallest supported pgsize */ + if (range.bitmap.pgsize != iommu_pgsize) { + ret = -EINVAL; + goto out_unlock; + } + if (range.iova & (iommu_pgsize - 1)) { + ret = -EINVAL; + goto out_unlock; + } + if (!range.size || range.size & (iommu_pgsize - 1)) { + ret = -EINVAL; + goto out_unlock; + } + + if (iommu->dirty_page_tracking) + ret = vfio_iova_dirty_bitmap(range.bitmap.data, + iommu, range.iova, range.size, + range.bitmap.pgsize); + else + ret = -EINVAL; +out_unlock: + mutex_unlock(&iommu->lock); + + return ret; + } } return -ENOTTY; @@ -2355,10 +2628,19 @@ static int vfio_iommu_type1_dma_rw_chunk(struct vfio_iommu *iommu, vaddr = dma->vaddr + offset; - if (write) + if (write) { *copied = copy_to_user((void __user *)vaddr, data, count) ? 0 : count; - else + if (*copied && iommu->dirty_page_tracking) { + unsigned long pgshift = __ffs(iommu->pgsize_bitmap); + /* + * Bitmap populated with the smallest supported page + * size + */ + bitmap_set(dma->bitmap, offset >> pgshift, + *copied >> pgshift); + } + } else *copied = copy_from_user(data, (void __user *)vaddr, count) ? 0 : count; if (kthread) From patchwork Thu May 14 20:37:45 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kirti Wankhede X-Patchwork-Id: 11549811 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A1601138A for ; Thu, 14 May 2020 21:11:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 89CD2206F1 for ; Thu, 14 May 2020 21:11:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="eMV9NEyc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728347AbgENVLo (ORCPT ); Thu, 14 May 2020 17:11:44 -0400 Received: from hqnvemgate26.nvidia.com ([216.228.121.65]:5574 "EHLO hqnvemgate26.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728073AbgENVLo (ORCPT ); Thu, 14 May 2020 17:11:44 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate26.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Thu, 14 May 2020 14:11:31 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Thu, 14 May 2020 14:11:44 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Thu, 14 May 2020 14:11:44 -0700 Received: from HQMAIL105.nvidia.com (172.20.187.12) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 14 May 2020 21:11:43 +0000 Received: from kwankhede-dev.nvidia.com (10.124.1.5) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Thu, 14 May 2020 21:11:37 +0000 From: Kirti Wankhede To: , CC: , , , , , , , , , , , , , , , , , , , , Kirti Wankhede Subject: [PATCH Kernel v20 6/8] vfio iommu: Update UNMAP_DMA ioctl to get dirty bitmap before unmap Date: Fri, 15 May 2020 02:07:45 +0530 Message-ID: <1589488667-9683-7-git-send-email-kwankhede@nvidia.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1589488667-9683-1-git-send-email-kwankhede@nvidia.com> References: <1589488667-9683-1-git-send-email-kwankhede@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1589490692; bh=izB/kfrbOkgeuoTy4WvibQk5KhK5lRPGhMmv3elCpMw=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:X-NVConfidentiality:MIME-Version: Content-Type; b=eMV9NEycBQ1zpD8foR+Y4AibzuuuOydDT555I9rJ027rrAjPx4wPovQ5u8Ct0H73B HXBCXOk0p0FMnunTSYcf+w26oqUtU+qv/zprfu7y2gWkORnG5amfz3XibO0MM7Dyn5 rQ+Exmq61pOeli4gWjWnJOwdJYqrd1DhvMEXvSxx+wUclJd1vYDlz4V0awhrlJ+LIN sjXSp3Do5jnHPmg5f/mfXz3c4oQkNwRAh5hspuKp7A4sv4bSA/OybYytYf9LY9Edhx SXd6sUitb0JbukPcutRuWY9igjdFkXAoaReeeeOlsE2Nuh5mobZULmwaCw/CSjvDzw 5MuFd4obrqtfQ== Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org DMA mapped pages, including those pinned by mdev vendor drivers, might get unpinned and unmapped while migration is active and device is still running. For example, in pre-copy phase while guest driver could access those pages, host device or vendor driver can dirty these mapped pages. Such pages should be marked dirty so as to maintain memory consistency for a user making use of dirty page tracking. To get bitmap during unmap, user should allocate memory for bitmap, set it all zeros, set size of allocated memory, set page size to be considered for bitmap and set flag VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP. Signed-off-by: Kirti Wankhede Reviewed-by: Neo Jia --- drivers/vfio/vfio_iommu_type1.c | 77 ++++++++++++++++++++++++++++++++++------- include/uapi/linux/vfio.h | 10 ++++++ 2 files changed, 75 insertions(+), 12 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index b76d3b14abfd..a1dc57bcece5 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -195,11 +195,15 @@ static void vfio_unlink_dma(struct vfio_iommu *iommu, struct vfio_dma *old) static int vfio_dma_bitmap_alloc(struct vfio_dma *dma, size_t pgsize) { uint64_t npages = dma->size / pgsize; + size_t bitmap_size; if (npages > DIRTY_BITMAP_PAGES_MAX) return -EINVAL; - dma->bitmap = kvzalloc(DIRTY_BITMAP_BYTES(npages), GFP_KERNEL); + /* Allocate extra 64 bits which are used for bitmap manipulation */ + bitmap_size = DIRTY_BITMAP_BYTES(npages) + sizeof(u64); + + dma->bitmap = kvzalloc(bitmap_size, GFP_KERNEL); if (!dma->bitmap) return -ENOMEM; @@ -999,23 +1003,25 @@ static int verify_bitmap_size(uint64_t npages, uint64_t bitmap_size) } static int vfio_dma_do_unmap(struct vfio_iommu *iommu, - struct vfio_iommu_type1_dma_unmap *unmap) + struct vfio_iommu_type1_dma_unmap *unmap, + struct vfio_bitmap *bitmap) { - uint64_t mask; struct vfio_dma *dma, *dma_last = NULL; - size_t unmapped = 0; + size_t unmapped = 0, pgsize; int ret = 0, retries = 0; + unsigned long pgshift; mutex_lock(&iommu->lock); - mask = ((uint64_t)1 << __ffs(iommu->pgsize_bitmap)) - 1; + pgshift = __ffs(iommu->pgsize_bitmap); + pgsize = (size_t)1 << pgshift; - if (unmap->iova & mask) { + if (unmap->iova & (pgsize - 1)) { ret = -EINVAL; goto unlock; } - if (!unmap->size || unmap->size & mask) { + if (!unmap->size || unmap->size & (pgsize - 1)) { ret = -EINVAL; goto unlock; } @@ -1026,9 +1032,15 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, goto unlock; } - WARN_ON(mask & PAGE_MASK); -again: + /* When dirty tracking is enabled, allow only min supported pgsize */ + if ((unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) && + (!iommu->dirty_page_tracking || (bitmap->pgsize != pgsize))) { + ret = -EINVAL; + goto unlock; + } + WARN_ON((pgsize - 1) & PAGE_MASK); +again: /* * vfio-iommu-type1 (v1) - User mappings were coalesced together to * avoid tracking individual mappings. This means that the granularity @@ -1066,6 +1078,7 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, ret = -EINVAL; goto unlock; } + dma = vfio_find_dma(iommu, unmap->iova + unmap->size - 1, 0); if (dma && dma->iova + dma->size != unmap->iova + unmap->size) { ret = -EINVAL; @@ -1083,6 +1096,23 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, if (dma->task->mm != current->mm) break; + if ((unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) && + (dma_last != dma)) { + + /* + * mark all pages dirty if all pages are pinned and + * mapped + */ + if (dma->iommu_mapped) + bitmap_set(dma->bitmap, 0, + dma->size >> pgshift); + + ret = update_user_bitmap(bitmap->data, dma, + unmap->iova, pgsize); + if (ret) + break; + } + if (!RB_EMPTY_ROOT(&dma->pfn_list)) { struct vfio_iommu_type1_dma_unmap nb_unmap; @@ -2447,17 +2477,40 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, } else if (cmd == VFIO_IOMMU_UNMAP_DMA) { struct vfio_iommu_type1_dma_unmap unmap; - long ret; + struct vfio_bitmap bitmap = { 0 }; + int ret; minsz = offsetofend(struct vfio_iommu_type1_dma_unmap, size); if (copy_from_user(&unmap, (void __user *)arg, minsz)) return -EFAULT; - if (unmap.argsz < minsz || unmap.flags) + if (unmap.argsz < minsz || + unmap.flags & ~VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) return -EINVAL; - ret = vfio_dma_do_unmap(iommu, &unmap); + if (unmap.flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) { + unsigned long pgshift; + + if (unmap.argsz < (minsz + sizeof(bitmap))) + return -EINVAL; + + if (copy_from_user(&bitmap, + (void __user *)(arg + minsz), + sizeof(bitmap))) + return -EFAULT; + + if (!access_ok((void __user *)bitmap.data, bitmap.size)) + return -EINVAL; + + pgshift = __ffs(bitmap.pgsize); + ret = verify_bitmap_size(unmap.size >> pgshift, + bitmap.size); + if (ret) + return ret; + } + + ret = vfio_dma_do_unmap(iommu, &unmap, &bitmap); if (ret) return ret; diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 123de3bc2dce..0a0c7315ddd6 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -1048,12 +1048,22 @@ struct vfio_bitmap { * field. No guarantee is made to the user that arbitrary unmaps of iova * or size different from those used in the original mapping call will * succeed. + * VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP should be set to get dirty bitmap + * before unmapping IO virtual addresses. When this flag is set, user must + * provide data[] as structure vfio_bitmap. User must allocate memory to get + * bitmap, zero the bitmap memory and must set size of allocated memory in + * vfio_bitmap.size field. A bit in bitmap represents one page of user provided + * page size in 'pgsize', consecutively starting from iova offset. Bit set + * indicates page at that offset from iova is dirty. Bitmap of pages in the + * range of unmapped size is returned in vfio_bitmap.data */ struct vfio_iommu_type1_dma_unmap { __u32 argsz; __u32 flags; +#define VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP (1 << 0) __u64 iova; /* IO virtual address */ __u64 size; /* Size of mapping (bytes) */ + __u8 data[]; }; #define VFIO_IOMMU_UNMAP_DMA _IO(VFIO_TYPE, VFIO_BASE + 14) From patchwork Thu May 14 20:37:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kirti Wankhede X-Patchwork-Id: 11549813 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 41097138A for ; Thu, 14 May 2020 21:11:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 26C112065C for ; Thu, 14 May 2020 21:11:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="qskyBTjj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728354AbgENVLv (ORCPT ); Thu, 14 May 2020 17:11:51 -0400 Received: from hqnvemgate26.nvidia.com ([216.228.121.65]:5587 "EHLO hqnvemgate26.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727873AbgENVLv (ORCPT ); Thu, 14 May 2020 17:11:51 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate26.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Thu, 14 May 2020 14:11:38 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Thu, 14 May 2020 14:11:50 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Thu, 14 May 2020 14:11:50 -0700 Received: from HQMAIL105.nvidia.com (172.20.187.12) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 14 May 2020 21:11:50 +0000 Received: from kwankhede-dev.nvidia.com (10.124.1.5) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Thu, 14 May 2020 21:11:44 +0000 From: Kirti Wankhede To: , CC: , , , , , , , , , , , , , , , , , , , , "Kirti Wankhede" Subject: [PATCH Kernel v20 7/8] vfio iommu: Add migration capability to report supported features Date: Fri, 15 May 2020 02:07:46 +0530 Message-ID: <1589488667-9683-8-git-send-email-kwankhede@nvidia.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1589488667-9683-1-git-send-email-kwankhede@nvidia.com> References: <1589488667-9683-1-git-send-email-kwankhede@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1589490698; bh=7/FHdy4SAIGMgoLkaA5oW8uu18Kdw+ZqC1L5LJHsD+8=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:X-NVConfidentiality:MIME-Version: Content-Type; b=qskyBTjj/xsk77LFTmyE6HqCbb9PSWwGs0/KuXSskJB3oZ9XrvA9O3+rTU6OBcRiL nufYmdIbzZL69LOzZ0TmH/ZcxFeVFmBDnogdcnI1B+AiZoriJSD9UR9EYkiBdrGGZ+ QFcUgcq/lazeuOBehLDRxUnEOZi6UFPCLVHBMH4r4RGO0SPh5gYoZ/1l5Lg3IHhg7+ dTyM2/YpngcB9EF4MermvheI7UgAAppef1v4yNawWqkpic4Q3SKaXBAUhMsTS8w99t ZPmHmnpEWOWiMWXyy48gbcZaqZHSHzf9H0jNopQn2EGs1Vl51AfgRp+mIBb9BTvcO3 sX9OEoWuRTCKA== Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Added migration capability in IOMMU info chain. User application should check IOMMU info chain for migration capability to use dirty page tracking feature provided by kernel module. User application must check page sizes supported and maximum dirty bitmap size returned by this capability structure for ioctls used to get dirty bitmap. Signed-off-by: Kirti Wankhede --- drivers/vfio/vfio_iommu_type1.c | 23 ++++++++++++++++++++++- include/uapi/linux/vfio.h | 22 ++++++++++++++++++++++ 2 files changed, 44 insertions(+), 1 deletion(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index a1dc57bcece5..3edb3c3e6170 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -2387,6 +2387,22 @@ static int vfio_iommu_iova_build_caps(struct vfio_iommu *iommu, return ret; } +static int vfio_iommu_migration_build_caps(struct vfio_iommu *iommu, + struct vfio_info_cap *caps) +{ + struct vfio_iommu_type1_info_cap_migration cap_mig; + + cap_mig.header.id = VFIO_IOMMU_TYPE1_INFO_CAP_MIGRATION; + cap_mig.header.version = 1; + + cap_mig.flags = 0; + /* support minimum pgsize */ + cap_mig.pgsize_bitmap = (size_t)1 << __ffs(iommu->pgsize_bitmap); + cap_mig.max_dirty_bitmap_size = DIRTY_BITMAP_SIZE_MAX; + + return vfio_info_add_capability(caps, &cap_mig.header, sizeof(cap_mig)); +} + static long vfio_iommu_type1_ioctl(void *iommu_data, unsigned int cmd, unsigned long arg) { @@ -2433,8 +2449,13 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, info.iova_pgsizes = iommu->pgsize_bitmap; - ret = vfio_iommu_iova_build_caps(iommu, &caps); + ret = vfio_iommu_migration_build_caps(iommu, &caps); + + if (!ret) + ret = vfio_iommu_iova_build_caps(iommu, &caps); + mutex_unlock(&iommu->lock); + if (ret) return ret; diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 0a0c7315ddd6..ab1d0150bbd3 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -1013,6 +1013,28 @@ struct vfio_iommu_type1_info_cap_iova_range { struct vfio_iova_range iova_ranges[]; }; +/* + * The migration capability allows to report supported features for migration. + * + * The structures below define version 1 of this capability. + * + * The existence of this capability indicates IOMMU kernel driver supports + * dirty page tracking. + * + * pgsize_bitmap: Kernel driver returns supported page sizes bitmap for dirty + * page tracking. + * max_dirty_bitmap_size: Kernel driver returns maximum supported dirty bitmap + * size in bytes to be used by user application for ioctls to get dirty bitmap. + */ +#define VFIO_IOMMU_TYPE1_INFO_CAP_MIGRATION 1 + +struct vfio_iommu_type1_info_cap_migration { + struct vfio_info_cap_header header; + __u32 flags; + __u64 pgsize_bitmap; + __u64 max_dirty_bitmap_size; /* in bytes */ +}; + #define VFIO_IOMMU_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12) /** From patchwork Thu May 14 20:37:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kirti Wankhede X-Patchwork-Id: 11549815 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6D6AC697 for ; Thu, 14 May 2020 21:11:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 467DF206F1 for ; Thu, 14 May 2020 21:11:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="RdS/qx+D" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728361AbgENVL6 (ORCPT ); Thu, 14 May 2020 17:11:58 -0400 Received: from hqnvemgate24.nvidia.com ([216.228.121.143]:14383 "EHLO hqnvemgate24.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728053AbgENVL6 (ORCPT ); Thu, 14 May 2020 17:11:58 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate24.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Thu, 14 May 2020 14:09:40 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Thu, 14 May 2020 14:11:57 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Thu, 14 May 2020 14:11:57 -0700 Received: from HQMAIL105.nvidia.com (172.20.187.12) by HQMAIL109.nvidia.com (172.20.187.15) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 14 May 2020 21:11:57 +0000 Received: from kwankhede-dev.nvidia.com (10.124.1.5) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Thu, 14 May 2020 21:11:50 +0000 From: Kirti Wankhede To: , CC: , , , , , , , , , , , , , , , , , , , , "Kirti Wankhede" Subject: [PATCH Kernel v20 8/8] vfio: Selective dirty page tracking if IOMMU backed device pins pages Date: Fri, 15 May 2020 02:07:47 +0530 Message-ID: <1589488667-9683-9-git-send-email-kwankhede@nvidia.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1589488667-9683-1-git-send-email-kwankhede@nvidia.com> References: <1589488667-9683-1-git-send-email-kwankhede@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1589490580; bh=A6ynUx4RRN9aiA5IiNYb6Ww2Ck+usdLG1MDrxk9TX4Y=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:X-NVConfidentiality:MIME-Version: Content-Type; b=RdS/qx+DfbJY6fhkjfcWbKgBYEPsYCXZbF/bZHKdjp6Z8Ur8LWdcennTYGOx7N32I nLGXtljYrIjgrX3U9QxYoGIIzrP672L7QA3TUISVVvNip+Kg6sUNRzarA3+LudlaH+ CPviKmJzRlm9aSIEhb0ExuQ8le98f3DMnXDMbhi75yqvLPcgJqEO9Zki9lHET9oqFh T9S+jiQ1LDi14oA2G09Fil0bVBzBnB+3Czu4zPd0NTp7NoWwoZ6mcXUgP1oBPUdsY1 KemLdfttR9OtBesoq4gKh2ajtKiGgqbiDGILVA6oHkyMBgi2u0E+h1dAF+vaBF8Fc2 L6Tx532ZceOeA== Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Added a check such that only singleton IOMMU groups can pin pages. From the point when vendor driver pins any pages, consider IOMMU group dirty page scope to be limited to pinned pages. To optimize to avoid walking list often, added flag pinned_page_dirty_scope to indicate if all of the vfio_groups for each vfio_domain in the domain_list dirty page scope is limited to pinned pages. This flag is updated on first pinned pages request for that IOMMU group and on attaching/detaching group. Signed-off-by: Kirti Wankhede Reviewed-by: Neo Jia --- drivers/vfio/vfio.c | 13 +++-- drivers/vfio/vfio_iommu_type1.c | 104 ++++++++++++++++++++++++++++++++++++---- include/linux/vfio.h | 4 +- 3 files changed, 109 insertions(+), 12 deletions(-) diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 765e0e5d83ed..580099afeaff 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -85,6 +85,7 @@ struct vfio_group { atomic_t opened; wait_queue_head_t container_q; bool noiommu; + unsigned int dev_counter; struct kvm *kvm; struct blocking_notifier_head notifier; }; @@ -555,6 +556,7 @@ struct vfio_device *vfio_group_create_device(struct vfio_group *group, mutex_lock(&group->device_lock); list_add(&device->group_next, &group->device_list); + group->dev_counter++; mutex_unlock(&group->device_lock); return device; @@ -567,6 +569,7 @@ static void vfio_device_release(struct kref *kref) struct vfio_group *group = device->group; list_del(&device->group_next); + group->dev_counter--; mutex_unlock(&group->device_lock); dev_set_drvdata(device->dev, NULL); @@ -1945,6 +1948,9 @@ int vfio_pin_pages(struct device *dev, unsigned long *user_pfn, int npage, if (!group) return -ENODEV; + if (group->dev_counter > 1) + return -EINVAL; + ret = vfio_group_add_container_user(group); if (ret) goto err_pin_pages; @@ -1952,7 +1958,8 @@ int vfio_pin_pages(struct device *dev, unsigned long *user_pfn, int npage, container = group->container; driver = container->iommu_driver; if (likely(driver && driver->ops->pin_pages)) - ret = driver->ops->pin_pages(container->iommu_data, user_pfn, + ret = driver->ops->pin_pages(container->iommu_data, + group->iommu_group, user_pfn, npage, prot, phys_pfn); else ret = -ENOTTY; @@ -2050,8 +2057,8 @@ int vfio_group_pin_pages(struct vfio_group *group, driver = container->iommu_driver; if (likely(driver && driver->ops->pin_pages)) ret = driver->ops->pin_pages(container->iommu_data, - user_iova_pfn, npage, - prot, phys_pfn); + group->iommu_group, user_iova_pfn, + npage, prot, phys_pfn); else ret = -ENOTTY; diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index 3edb3c3e6170..a52c4ae8907b 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -73,6 +73,7 @@ struct vfio_iommu { bool v2; bool nesting; bool dirty_page_tracking; + bool pinned_page_dirty_scope; }; struct vfio_domain { @@ -100,6 +101,7 @@ struct vfio_group { struct iommu_group *iommu_group; struct list_head next; bool mdev_group; /* An mdev group */ + bool pinned_page_dirty_scope; }; struct vfio_iova { @@ -143,6 +145,10 @@ struct vfio_regions { static int put_pfn(unsigned long pfn, int prot); +static struct vfio_group *vfio_iommu_find_iommu_group(struct vfio_iommu *iommu, + struct iommu_group *iommu_group); + +static void update_pinned_page_dirty_scope(struct vfio_iommu *iommu); /* * This code handles mapping and unmapping of user data buffers * into DMA'ble space using the IOMMU @@ -590,11 +596,13 @@ static int vfio_unpin_page_external(struct vfio_dma *dma, dma_addr_t iova, } static int vfio_iommu_type1_pin_pages(void *iommu_data, + struct iommu_group *iommu_group, unsigned long *user_pfn, int npage, int prot, unsigned long *phys_pfn) { struct vfio_iommu *iommu = iommu_data; + struct vfio_group *group; int i, j, ret; unsigned long remote_vaddr; struct vfio_dma *dma; @@ -667,8 +675,14 @@ static int vfio_iommu_type1_pin_pages(void *iommu_data, (vpfn->iova - dma->iova) >> pgshift, 1); } } - ret = i; + + group = vfio_iommu_find_iommu_group(iommu, iommu_group); + if (!group->pinned_page_dirty_scope) { + group->pinned_page_dirty_scope = true; + update_pinned_page_dirty_scope(iommu); + } + goto pin_done; pin_unwind: @@ -966,9 +980,11 @@ static int vfio_iova_dirty_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu, int ret; while ((dma = vfio_find_dma(iommu, i, sz))) { - - /* mark all pages dirty if all pages are pinned and mapped. */ - if (dma->iommu_mapped) + /* + * mark all pages dirty if any IOMMU capable device is not able + * to report dirty pages and all pages are pinned and mapped. + */ + if (!iommu->pinned_page_dirty_scope && dma->iommu_mapped) bitmap_set(dma->bitmap, 0, dma->size >> pgshift); ret = update_user_bitmap(bitmap, dma, iova, pgsize); @@ -986,7 +1002,6 @@ static int vfio_iova_dirty_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu, i = dma->iova + dma->size; if (i >= limit) break; - sz = limit - i; } @@ -1100,10 +1115,12 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu, (dma_last != dma)) { /* - * mark all pages dirty if all pages are pinned and - * mapped + * mark all pages dirty if any IOMMU capable device is + * not able to report dirty pages and all pages are + * pinned and mapped. */ - if (dma->iommu_mapped) + if (!iommu->pinned_page_dirty_scope && + dma->iommu_mapped) bitmap_set(dma->bitmap, 0, dma->size >> pgshift); @@ -1485,6 +1502,51 @@ static struct vfio_group *find_iommu_group(struct vfio_domain *domain, return NULL; } +static struct vfio_group *vfio_iommu_find_iommu_group(struct vfio_iommu *iommu, + struct iommu_group *iommu_group) +{ + struct vfio_domain *domain; + struct vfio_group *group = NULL; + + list_for_each_entry(domain, &iommu->domain_list, next) { + group = find_iommu_group(domain, iommu_group); + if (group) + return group; + } + + if (iommu->external_domain) + group = find_iommu_group(iommu->external_domain, iommu_group); + + return group; +} + +static void update_pinned_page_dirty_scope(struct vfio_iommu *iommu) +{ + struct vfio_domain *domain; + struct vfio_group *group; + + list_for_each_entry(domain, &iommu->domain_list, next) { + list_for_each_entry(group, &domain->group_list, next) { + if (!group->pinned_page_dirty_scope) { + iommu->pinned_page_dirty_scope = false; + return; + } + } + } + + if (iommu->external_domain) { + domain = iommu->external_domain; + list_for_each_entry(group, &domain->group_list, next) { + if (!group->pinned_page_dirty_scope) { + iommu->pinned_page_dirty_scope = false; + return; + } + } + } + + iommu->pinned_page_dirty_scope = true; +} + static bool vfio_iommu_has_sw_msi(struct list_head *group_resv_regions, phys_addr_t *base) { @@ -1892,6 +1954,16 @@ static int vfio_iommu_type1_attach_group(void *iommu_data, list_add(&group->next, &iommu->external_domain->group_list); + /* + * Non-iommu backed group cannot dirty memory directly, + * it can only use interfaces that provide dirty + * tracking. + * The iommu scope can only be promoted with the + * addition of a dirty tracking group. + */ + group->pinned_page_dirty_scope = true; + if (!iommu->pinned_page_dirty_scope) + update_pinned_page_dirty_scope(iommu); mutex_unlock(&iommu->lock); return 0; @@ -2015,6 +2087,13 @@ static int vfio_iommu_type1_attach_group(void *iommu_data, done: /* Delete the old one and insert new iova list */ vfio_iommu_iova_insert_copy(iommu, &iova_copy); + + /* + * An iommu backed group can dirty memory directly and therefore + * demotes the iommu scope until it declares itself dirty tracking + * capable via the page pinning interface. + */ + iommu->pinned_page_dirty_scope = false; mutex_unlock(&iommu->lock); vfio_iommu_resv_free(&group_resv_regions); @@ -2167,6 +2246,7 @@ static void vfio_iommu_type1_detach_group(void *iommu_data, struct vfio_iommu *iommu = iommu_data; struct vfio_domain *domain; struct vfio_group *group; + bool update_dirty_scope = false; LIST_HEAD(iova_copy); mutex_lock(&iommu->lock); @@ -2174,6 +2254,7 @@ static void vfio_iommu_type1_detach_group(void *iommu_data, if (iommu->external_domain) { group = find_iommu_group(iommu->external_domain, iommu_group); if (group) { + update_dirty_scope = !group->pinned_page_dirty_scope; list_del(&group->next); kfree(group); @@ -2203,6 +2284,7 @@ static void vfio_iommu_type1_detach_group(void *iommu_data, continue; vfio_iommu_detach_group(domain, group); + update_dirty_scope = !group->pinned_page_dirty_scope; list_del(&group->next); kfree(group); /* @@ -2234,6 +2316,12 @@ static void vfio_iommu_type1_detach_group(void *iommu_data, vfio_iommu_iova_free(&iova_copy); detach_group_done: + /* + * Removal of a group without dirty tracking may allow the iommu scope + * to be promoted. + */ + if (update_dirty_scope) + update_pinned_page_dirty_scope(iommu); mutex_unlock(&iommu->lock); } diff --git a/include/linux/vfio.h b/include/linux/vfio.h index 5d92ee15d098..38d3c6a8dc7e 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -76,7 +76,9 @@ struct vfio_iommu_driver_ops { struct iommu_group *group); void (*detach_group)(void *iommu_data, struct iommu_group *group); - int (*pin_pages)(void *iommu_data, unsigned long *user_pfn, + int (*pin_pages)(void *iommu_data, + struct iommu_group *group, + unsigned long *user_pfn, int npage, int prot, unsigned long *phys_pfn); int (*unpin_pages)(void *iommu_data,